Closure Arrangement for Cans

ABSTRACT

The can of the invention includes a body portion joined to a neck portion of reduced contour and which incorporates an outer peripheral projection and which defines an upper opening; and a lid having a peripheral tubular portion to be fitted into the upper opening, and an outer circumferential rib. The outer circumferential rib presents a semi-tubular shape, inferiorly opened and having: a radially inner edge which is joined to the upper edge of the peripheral tubular portion of the lid, by an annular step; and a radially outer edge. The outer circumferential rib carries, in its interior, an annular gasket to be seated on the outer peripheral projection of the neck portion, upon the fitting of the lid into the upper opening and the seating of the annular step on said outer peripheral projection.

FIELD OF THE INVENTION

The present invention refers to a closure arrangement to be applied to cans formed in metallic sheet and comprising a tubular body portion, generally presenting a circular section and carrying a bottom wall, an upper neck portion with a contour smaller than that of the body portion, and a transition portion joining the body portion and neck portion and having an end edge which defines the contour of an upper opening for the can, on which is fitted a removable lid.

PRIOR ART

There are well known from the prior art the tubular cans obtained in metallic sheet and comprising a body portion, of circular or polygonal cross-section and carrying a bottom wall and an annular upper wall which are peripherally attached, generally by double-seaming, to the lower end edge and upper end edge of the can.

This type of construction, which is well known in the art, allows the bottom wall and the annular upper wall to exert a function of structuring the body portion of the can, without requiring the incorporation of additional stiffening structural elements. This type of can has the body portion presenting a cross-section which is constant or progressively reduced from the bottom wall to the annular upper wall, the thickness of the metallic sheet being dimensioned as a function of this structural configuration of the can.

There are also known cans which present a body portion of tubular section inferiorly carrying the bottom wall and which is superiorly joined, through a transition portion, to a neck portion of smaller contour, to whose free upper end edge is double-seamed the peripheral edge of an annular upper wall.

In the can construction in which the body portion extends from one end edge to the other with the same cross-section, the provision of the annular upper wall is fundamental for obtaining the adequate structural resistance of the can, through a metallic sheet of adequate minimum thickness. Without the annular upper wall, the thickness of the metallic sheet of the body portion would have to be considerably increased, with the consequent increase in the cost of the raw material and in the weight of the can.

On the other hand, in cans comprising a body portion and a neck portion of reduced cross-section and height, joined by a frusto-conical or frusto-pyramidal transition portion only slightly spaced from the upper end edge of the can, the provision of the transition portion in the upper region of the can provides a substantial increase in the structural resistance of the latter, allowing eliminating the annular upper wall, with the upper opening of the can corresponding to the inner cross-section of the neck portion. In this construction, it is sufficient that the upper end edge of the can, i.e., of the neck portion, be bent or otherwise worked to form a curl or outer peripheral projection, surrounding the upper opening of the can and defining, jointly with the upper end edge of the latter, a seat for seating a removable lid, comprising a panel portion which incorporates a peripheral tubular portion to be tightly fitted, with interference, in the upper opening, in the interior of the neck portion, said peripheral tubular portion having a free upper edge which is bent, or otherwise worked, to form a curl or outer circumferential rib, to be seated onto the upper end edge of the can, upon the closing of the lid.

This prior art construction allows eliminating the annular upper wall and forming an initial tubular body, with a metallic sheet of usual thickness, for example from about 0.21 mm to about 0.27 mm for 3.6 liter cans, and presenting a cross-section corresponding to that of the neck portion. Subsequently, said tubular body is submitted to an expansion operation, through which are formed the transition portion and the body portion, the latter presenting a concentric cross-section, similar to and larger than that of the neck portion. Thus, it is possible to obtain a can with less metallic sheet consumption.

In spite of the above-mentioned advantages for cans provided with a neck portion of reduced section and without an annular upper wall, this prior art construction presents the drawback of not guaranteeing a high and reliable tightness degree in the closure of the lid.

Further to the sealing aspect commented above, in this known can construction, the junction region, in an externally concave arc, of the transition portion with the neck portion defines a region with a lower can resistance to the compression axial forces that occur in the filling line, upon the closure of the lid or the mounting of a seal and suspension ring, in the cases in which the latter is provided. The more the cross-section contour of the neck portion is reduced in relation to the body portion, for a given height of the transition portion, the more accentuated will be the relative structural fragility of the can against compression axial forces. This constructive particularity usually affects, restrictively, the can structural resistance upon stacking.

As a function of the inconveniences mentioned above, it was proposed the constructive solution described and claimed in patent application BR PI 0705211-1 (PCT/BR2008/000334), of the same applicant and according to which, a outer circumferential rib of the lid carries, interiorly, an annular gasket, for example, a resin bead, to be seated onto the upper end edge of the neck portion upon closing the lid by fitting into the upper opening.

Although the provision of said annular gasket provides an adequate tightness degree in the closure of the lid in the upper opening of the can, it leads to an undesirably complex and difficult to control operations for applying the gasket, in the form of a resin bead under the outer circumferential rib of the lid.

In said previous construction, the outer circumferential rib of the lid takes the form of a tubular curl, defining a lower convex surface portion, onto which must be correctly and controllably applied the resin bead, made of, for example, “Plastisol”, which will define the gasket. It is difficult to control the borders of the resin bead onto the lower convex surface of the outer circumferential rib of the lid, which fact impairs or even avoids obtaining a desired quality standard.

In this previous solution, the outer circumferential rib of the lid defines a stop which is seated on the outer peripheral projection of the can, in order to limit the fitting of the lid into the upper opening of the can, during the lid closure operations. Thus, the tubular shape of the outer circumferential rib allows the latter to resist the forces applied over the lid, during its automated closure in the filling line or even upon its manual closure during the progressive consumption of the canned product. Even compromising the application of the sealing gasket, the tubular shape of the outer circumferential rib is a structural requirement to comply with the function of limiting the fitting of the lid into the upper opening of the can.

SUMMARY OF THE INVENTION

Due to the operational difficulties to provide a sealing gasket for the lid of a can of the type considered herein, the present invention has the main object of providing a closure arrangement for this type of can, which is easy to execute and reliable in terms of quality standards, and which presents a high tightness degree, even admitting larger dimensional tolerances in the formation of the upper opening of the neck portion and of the lid, without submitting the outer circumferential rib of the lid to the forces to be applied the latter during its closure in the upper opening of the can.

These and other objects of the invention are attained with a closure arrangement applied to cans of the type which comprises: an inferiorly closed body portion; a neck portion, presenting a reduced contour and an upper end edge, which incorporates an outer peripheral projection and defines the contour of an upper opening; a transition portion, joining the body portion and the neck portion; and a lid having a panel portion which incorporates a peripheral tubular portion to be fitted, with interference, in said upper opening and having an upper edge carrying an outer circumferential rib.

According to the invention, the outer circumferential rib presents a semi-tubular shape, inferiorly opened and having: a radially inner edge which is joined to the upper edge of the peripheral tubular portion of the lid, by an annular step which projects outwards from said peripheral tubular portion; and a radially outer edge, spaced from the radially inner edge, the outer circumferential rib carrying, in its interior, an annular gasket to be seated and pressed against the outer peripheral projection of the neck portion, upon fitting the lid in the upper opening and seating the annular step on the outer peripheral projection of the neck portion.

According to the closure arrangement of the present invention, the outer circumferential rib of the lid has its tubular shape inferiorly opened, so as to allow the interior thereof to easily house an annular gasket, for example, a resin bead, to be seated and pressed against the outer peripheral projection of the neck portion. The provision of the annular step, to be seated on the outer peripheral projection of the neck, allows limiting the fitting of the lid into the upper opening of the can and prevents excessive deformation of the semi-tubular outer circumferential rib, upon pressing the lid against the can body.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described below, with reference to the enclosed drawings, given by way of example of a possible embodiment of the invention and in which:

FIG. 1 represents an upper plan view of a can, in the condition in which it is closed by a lid, the latter being retained, in its closed condition, by a retaining ring peripherally locked under the outer peripheral projection of the can;

FIG. 2 represents a partial longitudinal sectional view of the can illustrated in FIG. 1, said section taken according to line II-II in said previous figure, the lid being in a partially closed position and the retaining ring being in an exploded condition;

FIG. 2A represents an enlarged detail of the upper portion of the assembly illustrated in FIG. 2 and deprived of the retaining ring;

FIG. 3 represents a view similar to that of FIG. 2, but illustrating the lid and the retaining ring mounted to the can; and

FIG. 3A represents an enlarged detail of the upper portion of the assembly illustrated in FIG. 3.

DESCRIPTION OF THE INVENTION

As already previously described and illustrated in the enclosed drawings, the closure arrangement proposed by the invention is applied to a can 10 formed in metallic sheet, generally tinplate, presenting a generally circular cross-section, but which can be polygonal, although not being illustrated in the drawings.

The tubular shaped can 10 comprises: a body portion 11, in whose lower end edge 11 a is affixed, generally by double-seaming, the peripheral edge of a bottom wall 12; a neck portion 13 having a concentric contour, which is similar and reduced in relation to that of the body portion 11, and an upper end edge 13 a defining the contour of an upper opening A for the can 10; and a transition portion 14 with a profile inclined in relation to the axis of the can 10 and joining the body portion 11 and the neck portion 13.

The upper end edge 13 a of the neck portion 13 incorporates an outer peripheral projection 15. In the illustrated condition, the outer peripheral projection 15 takes the form of a curl of tubular cross-section, obtained by bending the metallic sheet radially outwards in the region of the upper end edge 13 a. In the drawings, the cross-section of the curl is circular, but it should be understood that a peripheral projection with different cross-sections, tubular or not, can be formed.

The formation of the body portion 11 is initiated by forming a tubular body with a cross-section corresponding to that of the neck portion 13, and which is then radially expanded along part of its height, to define the body portion 11 and the transition portion 14, according to methods already known by the prior art. The transition portion 14 remains inferiorly joined to the body portion 11 by a junction region in convex arc 14 a and superiorly joined to the neck portion 13 by a junction region in concave arc 14 b.

The can 10 further comprises a lid 20 formed in a single piece of stamped metallic sheet, presenting a panel portion 21 occupying great part of the cross-section area of the upper opening A and incorporating a peripheral tubular portion 22 that is configured and dimensioned to be tightly fitted, with interference, in the upper opening A, in the interior of the neck portion 13. Said peripheral tubular portion 22 presents an upper edge 22 a in which is incorporated an outer circumferential rib 25 configured to be seated onto the outer peripheral projection 15 on the upper end edge 13 a of the neck portion 13.

As illustrated, the lid 20 is preferably constructed with its panel portion 21 incorporating a pending skirt 21 a which forms, with the peripheral tubular portion 22, a peripheral channel 24, of rectangular section, radially separating the panel portion 21 from the peripheral tubular portion 22, the panel portion 21 lying in a plane higher than that of the bottom wall 24 a of the peripheral channel 24.

According to the invention, the outer circumferential rib 25 presents a semi-tubular shape inferiorly opened and having: a radially inner edge 25 a, which is joined to the upper edge 22 a of the peripheral tubular portion 22 of the lid 20, by an annular step 26 which projects outwards from said peripheral tubular portion 22; and a radially outer edge 25 b, spaced from the radially inner edge 25 a, the outer circumferential rib 25 carrying, in its interior, an annular gasket 30, preferably in the form of a resin bead, for example made of “Plastisol”, molded in the interior of the outer circumferential rib 25 of the lid 20.

The annular gasket 30 is configured in the interior of the outer circumferential rib 25, to be seated and pressed against the outer peripheral projection 15 of the neck portion 13, upon the fitting of the lid 20 into the upper opening A of the can and the seating of the annular step 26 on the outer peripheral projection 15 of the neck portion 13.

Although the drawings illustrate only an outer circumferential rib 25 in the form of a semi-tubular curl, with a cross-section in the form of an arc of a circle, it should be understood that other forms of said cross-section other than those that present a perfect circular arc can be used.

According to the illustrated construction, the outer circumferential rib 25 has the projection of its radially inner edge 25 a, in the axial direction of the can, disposed secant to the radially innermost half contour of the outer peripheral projection 15 of the neck portion 13, the projection, in the same axial direction of the radially outer edge 25 b of the outer circumferential rib 25, being disposed radially external to the contour of the outer peripheral projection 15 of the neck portion 13.

Further according to the illustrated construction, the radially inner edge 25 a and the radially outer edge 25 b of the outer circumferential rib 25 define, therebetween, a alignment which is secant to the upper half of the contour of the outer peripheral projection 15 of the neck portion 13. This constructive form allows that, upon the fitting of the lid 20 into the upper opening A of the can, the upper portion of the contour of the outer peripheral projection 15 slightly penetrates in the interior of the lower contour of the outer circumferential rib 25, pressing the annular gasket 30 and guaranteeing a high tightness degree in the closure of the lid.

Aiming at imparting a certain interference degree between the annular gasket 30 and the upper portion of the outer peripheral projection 15, the annular gasket 30 is configured to be inferiorly tangent or intersected by the alignment defined by the radially inner edge 25 a and radially outer edge 25 b, of the outer circumferential rib 25 of the lid 20.

As illustrated in drawing figures, the present closure arrangement can further comprise a retaining ring 40, in a single piece of plastic material and having: an upper annular portion 41 to be seated on the outer circumferential rib 25 of the lid 20; a peripheral skirt portion 42 pending from the upper annular portion 41, laterally tightly surrounding the outer circumferential rib 25 of the lid 20 and the outer peripheral projection 15 of the neck portion 13 and incorporating an inner circumferential projection 43, to be seated and axially locked under the outer peripheral projection 15 of the neck portion 13.

In the illustrated embodiment, the inner circumferential projection 43 presents a profile in the form of downwardly and radially inwardly inclined ramp, to define a sort of a tooth actuating under the outer peripheral projection 15 of the neck portion 13, to provide a reliable axial locking of the lid 20 to the body portion 11 of the can 10.

The retaining ring 40 prevents the lid 20 from being removed, without evidencing the use of a lever tool supported in the outer peripheral projection 15.

Although not illustrated herein, the retaining ring 40 can have its upper annular portion 41 internally incorporating the diametrically opposed ends of a suspension handle to be displaced between a retracted inoperative position, coplanar or substantially coplanar to the upper annular portion 41, and an elevated operative position and obtained after the rupture of breakable bridges which connect a median portion of the handle to the upper annular portion of the lid.

In the illustrated constructive form, the retaining ring 40 further incorporates, in its upper annular portion 41, an upper tubular projection 46 positioned and dimensioned to be fitted against the bottom wall 12, internally to its peripheral double seam, of another identical can seated onto the first in a stack of said cans.

When the can is applied to contain paints, varnishes and similar products, the upper annular portion 41 of the retaining ring 40 can radially inwardly prolong in relation to the position of the upper tubular projection 46, to form a flap 41 a for scraping brushes and broaches when, after the withdrawal of the lid 20, the retaining ring 40 is reconducted to its axially locked position under the outer peripheral projection 15 of the neck portion 13. In cases in which the retaining ring 40 is provided with a suspension handle, its fitting on the can deprived of the lid, allows the can to be suspended by the handle of the retaining ring 40, while its content is progressively removed in a continuous painting operation.

Although illustrating only one embodiment of the present closure arrangement, it should be understood that said arrangement may be altered in the form and disposition of the component parts, without departing from the inventive concept defined in the claims that accompany the present disclosure. 

1. A closure arrangement for cans of the type which comprises: a body portion inferiorly closed; a neck portion, presenting a reduced contour and an upper end edge, which incorporates an outer peripheral projection and defines the contour of an upper opening; a transition portion, joining the body portion and the neck portion; and a lid having a panel portion which incorporates a peripheral tubular portion to be fitted, with interference, into said upper opening, and having an upper edge carrying an outer circumferential rib, the arrangement being characterized in that the outer circumferential rib presents a semi-tubular shape inferiorly opened and having: a radially inner edge which is joined to the upper edge of the peripheral tubular portion of the lid, by an annular step which projects outwards from said peripheral tubular portion; and a radially outer edge, spaced from the radially inner edge, the outer circumferential rib carrying, in its interior, an annular gasket to be seated and pressed against the outer peripheral projection of the neck portion upon the fitting of the lid into the upper opening (A) and the seating of the annular step on the outer peripheral projection of the neck portion.
 2. The closure arrangement, as set forth in claim 1, characterized in that the outer circumferential rib has the projection of its radially inner edge, in the axial direction of the can, secant to the radially innermost half contour of the outer peripheral projection of the neck portion, the projection, in the same axial direction of the radially outer edge of the outer circumferential rib, being disposed radially external to the contour of the outer peripheral projection of the neck portion.
 3. The closure arrangement, as set forth in claim 2, characterized in that the annular gasket is defined by a resin bead molded in the interior of the outer circumferential rib of the lid.
 4. The closure arrangement, as set forth in claim 1, characterized in that the radially inner edge and radially outer edge of the outer circumferential rib define, therebetween, an alignment which is secant to the upper half of the contour of the outer peripheral projection of the neck portion.
 5. The closure arrangement, as set forth in claim 4, characterized in that the annular gasket is inferiorly tangent to or intersected by the alignment defined by the inner radial edge and radially outer edge of the outer circumferential rib of the lid.
 6. The closure arrangement, as set forth in claim 1, characterized in that the outer peripheral projection and the outer circumferential rib are defined by radially outwardly bending the upper end edge of the neck portion and the free upper edge of the peripheral tubular portion of the lid, respectively.
 7. The closure arrangement, as set forth in claim 1, characterized in that it further comprises a retaining ring, in a single piece of plastic material and having: an upper annular portion to be seated on the outer circumferential rib of the lid; a peripheral skirt portion pending from the upper annular portion, laterally tightly surrounding the outer circumferential rib of the lid and the outer peripheral projection of the neck portion and incorporating an inner circumferential projection to be seated and axially locked under the outer peripheral projection of the neck portion.
 8. The closure arrangement, as set forth in claim 7, characterized in that the inner circumferential projection presents a profile in the form of a downwardly and radially inwardly inclined ramp.
 9. The closure arrangement, as set forth in claim 7, characterized in that the retaining ring also incorporates, in its upper annular portion, an upper tubular projection positioned and dimensioned to be fitted against the bottom wall, internally to the peripheral double-seam, of another identical can, seated on the first one in a stack of said cans. 